Mixed chlorobromo derivatives of indigo and process of making same.



' UNITE snares Parana easier...

GADIENT ENGI, OF BASEL, SWITZERLAND, ASSIGNOR TO THE FlRM OF SOCIETY OF CHEMICAL INDUSTRY IN BASLE, O1" BASEL, SWITZERL-XND.

'[IXED CHLOROBROMO DERIVATIVES OF INDIGO AND PROCESS OF JEAISTING SAL IE.

Specification of Letters Patent.

Patented Nov. a, 1907.

Application filed June 14. 1907. Serial No. 378.930.

dated March 23d 1907, l have described a rocessfor the manufacture of triand tetraromoderivatives of indigo consisting in treatin indigo, or monoor dibromindigo at a raisedtemperature with bromin in presence of a suitable indifferent diluent or solvent.

I have now found that in an analogous manner mixed chlorobromo derivatives of indigo ca be obtained by brominating the known monoand dichloro derivatives of indigo, whereby according to the chosen startmg material and to the quantity of brornin employed monochlorodibromindigo, mono chlorotribromindigo, dichloromonobrominof indigo show a great resemblance with the tribromoandtetrabromo derivatives of indigo described in the said ap lications for Letters Patent No. 364019 am: No. 364020. By' treatment with alkaline reducing agents, the new mixed chlorobromo derivatives of indigo yield a vat wherein unmordanted cotton is dyed bri ht violet to blue tints of excellent fastness. lhe manufacture of these new chlorobromo derivatives of indigo is illus: trated by the following examples.

Example I. 10 parts of monochlorindigo are suspended in 100 parts of nitrobenzene and mixed with 11 parts (abdut 4 atomic proportions) of bromin, and the whole is eated, in the course of about 1%; hours, in a reflux apparatus, in an oil bath, to a temperature of 226 0. this being the temperature of "the bath. The temperature is maintained at 226 228 for about 1+}- hours, during which time much hydrogen bromid is evolved. After cooli and filtering, the

' solid matter is washed with alcohol and dried.

A mixed chlorobromo-derivative of indigo is thus obtained, with very good yield, as a crystalline blue powder having a composition corresponding with that of a dibrommohaving a bronze reflex. centrated sulfuric acid to a blue solution nochlorindigo, (l lLO N tlBr This compound dissolves 1n concentrated sulfuric acid to a blue solution tending slightly to green;

addition of water to solution precipitates the dyestull' as blue flocks. Filming sulfuric. acid dissolves to a pure blue solution. Nitrobenzene and anilin dissolve it with difficulty when cold, but comparatively easily when hot, to a pure blue solution. llhen treated with the usual alkaline reducing agents in a vat, particularly with caustic soda (soda lye) and sodium hydrosul'l'itc, the dyostull' yields a clear yellow liquor dyeing cotton bright blue tints which may be further increased in brightness by a short soaping at 90 0., suchas by a bath containing 5 grams ol soap and 5 grams of sodium carbonate per liter. The soaped dycings are distinguished by an extraordinary fastness to washing, to chlorin and to light.

Example II. 10,parts of nmnochlorindigo are suspended in 100 parts of nitrobenzene and mixed with l7.5---22 parts of broimin (the theoretical quantity for 6 atomic proportions is 16.3 parts), the remaimilcr of the treatment being like that of the preceding example. After cooling and filtering, the solid matter is washed with alcohol and dried, there being. thus obtained a good yield of a tribromomonochlorindigo, in the form of small brownwiolet crystals It dissolves in contending slightly to green and in fuming sulfuric acid to pure blue solution which does not change even. when slightly heated. Anilin dissolves it with di'llioulty when cold to a green-blue solution and comparatively easily when hot to a pure blue solution; nitrobenzene dissolves it with dilliculty when cold to a urc blue solution, and'comparativelyeasi y when hot to a violet blue solution. In respect of tinctorial properties monochlorotribromindigo presents great analogy to the tetrabromindigo. The bright blue dyeings which the (.lyestull' yields in an alkaline vat also become more brilliant when subjected to a short soaping, and are dist-inguished by an excellent fastness to washing, chlorin and light. In analogous manner the dichloro derivatives of indigo maybe bromi noted, such as for exam )l(- the ortho--, meta-.

o n,o,n,oin

monobromoor dichlorodibromo derivatives I be noticed that theydye unmordanted cot ton from an alkaline vat blue tints fast to I of indigo are obtained.

Example III. 5 parts of paradichlorin- -digo prepared from orthonitroparachlorobenzaldehyde r 4-chloro-2-phenyl-glycin-1-car boXylic acid, are Well mixed with 50 parts of nitrobenzene and 5 parts of bromin (about 4 atomic proportions) and the mixture is heated in a reflux apparatus in an oil bath in such a manner that the temperature of the latter rises to 225 C. in the course of about an hour. Boiling is maintained for about 1%2 hours, the mass is allowed to cool and the solid product se arated by'filtration. After Washing with a cohol and drying the dichlorobromo derivative forms a blue-violet crystalline powder which dissolves in concentrated sulfuric acid to a red-brown solution; on diluting the 'solution blue-violet flocks are precipitated, Fuming sulfuric acid dissolves the dyestuff to a red-violet solution which passes in the course of time or on heating, to a blue-violet and finally to blue. In hot nitrobenzenc the dyestuff dissolves to a violet solution. By treating the dyestuif in a vat with alkaline reducing 11 cuts, a clear yellow liquor is obtained w ich dyes cotton without a mordant bright violet tints, fast to Washing and to chlorin.

If in this example, about 2.5 parts of bromin are employed, a dichloromonobromindigo of similar properties is obtained. Relatively to the dichloromonobromand dichlorodibromoderivatives obtained by br0mi-' nating orthoor meta-dichlorindigo, shall washing, light and chlorin.

What I claim is:

' 1. The described rocess for the manufac ture of miXe dc'hloro romo derivatives of indigo, which process consists in treating monoture of mixed chlorobromo derivatives of' in digo, which process consists in treating monoand dichlorindigo with bromm in presence -of nitrobenzene.

3. As new products the mixed chlorobromo derivatives of indigo which are obtained by treating mono and dichlorindigo with bromin, constituting in dry state from blue to violet powders, insoluble in water, diflicultly soluble in cold anilin and cold nitrobenzene, more easily in hot anilin and hot nitrobenzene with a blue to violet color, dissolving in'futning sulfuric acid withblue'to violet color, yielding yellowish vats by treatment with suitable reducing agents, from which vats unmordanted cotton is dyed in beautiful violet to blue shades, fast to Washing, light and chlorin.

In witness whereof I-have hereunto signed my name this 4 day of June,.190 7,,in the presence of two subscribin witnesses.

. .GATJIENT ENGI. 'Witnesses:

- GEO. GIF'FORD,

AMAND BITTER. 

